Selective Grinding and Denture Maintenance Protocols

Selective Grinding in Prosthodontics

Aim: The primary goal is to obtain Balanced Bilateral Occlusion (BBO) without causing changes to the Centric Relation (CR) or Vertical Dimension (VD).

Objectives of Occlusal Adjustment

• Achieve stability and maximum distribution of forces.
• Maintain the Vertical Dimension (VD).
• Ensure occlusal harmony and sharp cusps.
• Reduce lateral forces.

Rules for Correcting Premature Contacts

• Tooth movement causing a high cusp: For premature contact, lower the opposing fossa.
• Upper molars positioned buccally: Grind the upper buccal and palatal cusps, as well as the lower lingual and buccal cusps.
• Upper molars positioned lingually: Grind the buccal surface of the lower lingual cusp and the palatal surface of the upper buccal cusp.
• Premature contact in the upper palatal cusp: In centric, working, and non-working sides, reduce the opposing fossa except in all three positions.
• Maxillary and mandibular buccal cusps tripping on the working side: Reduce the palatal surface of the upper buccal cusp.
• Maxillary and mandibular lingual cusps tripping on the working side: Reduce the buccal surface of the lower lingual cusp.
• Both cusps tripping on the working side (no contact in non-working): Reduce the lingual surface of the upper buccal cusp and the buccal surface of the lower lingual cusp.

Denture Delivery and Clinical Adjustments

During denture delivery, perform necessary adjustments and corrections. Check the occlusion with articulator paper to achieve Balanced Bilateral Occlusion (BBO). This includes:

• Occlusal corrections and contour modifications.
• Elimination of areas with overpressure.
• Trimming sharp edges to prevent the formation of ulcers.

Patient Care and Maintenance Recommendations

For Removable Complete Dentures (RCD), patient learning is essential:

• Chewing: Avoid pushing the prosthesis with the tongue. Chew on both sides and start with soft foods.
• Pressure Points: If pressure points exist, the denture must be worn for 2 hours before the appointment.
• Phonetics: Engage in phonetics training.
• Hygiene: Use water, soap, and a brush after each meal to prevent Candida and stomatitis.
• Rest: Sleep without the denture to allow the gums to rest, avoiding stomatitis and Candida infections.

Follow-up Appointment Schedule

Regular follow-ups should occur at the following intervals:

• 7 days
• 30 days
• 1 year

Denture Breakage and Repair Techniques

When a breakage occurs, follow this technical procedure:

1. Inspection: Check that the fracture line fits perfectly and no material is lost.
2. Preparation: Create dovetail retentions for the new material. Do not touch the edges; focus only on the fracture line.
3. Splinting: Fix fragments with a metal stick (splint) using wax and glue on the fractured area.
4. Casting: Cast the tissue surface of the denture with plaster, applying a separating agent.
5. Resin Incorporation: Incorporate the resin (either autocurable or thermocurable).
6. Reinforcement: Metal mesh reinforcements can be added to increase resistance; once cured, the metal remains inside the resin.
7. Curing: Place the model in a pot of boiling water to cure.
8. Finishing: Once cured, remove the cast and plaster key. Polish the prosthesis with burs and rubbers to remove excess material.

Note: A color difference between the new and old resin may occur, but this is not a functional problem.